1. Field of the Invention
This invention relates to a method for treating urinary incontinence and an apparatus therefor in such a manner as to induce an eddy current in the physiological body by means of a magnetic stimulation coil which produce a magnetic pulsive flux under the suppliment of current pulses.
2. Description of the Related Art
Urinary incontinence or leakage of urine contrary to the patient's will has been neglected because it is not a disorder threatening the life of the patient. This urological malfunction, however, interferes often with everyday activities of the patient, and thus appropriate treating measures for it have been desired.
Such desire is especially manifest nowadays when aged population have been increasing rapidly, and patients with this bladder malfunction tend to grow in association. This malfunction is seen among children as well as among elderly people whether they are men or women, and patients with spinal cord injuries often resulting from traffic accidents are also frequently afflicted with this malfunction. Such tendencies spur the urge toward a good remedy for this involuntary leakage of urine because such remedy would be greatly helpful for the improvement of quality of life of the patient.
Conventional methods for treating urinary incontinence include, besides those dependent on the use of medication or surgery, the electric stimulation which consists of applying stimulating electrodes to the patient, and delivering electric pulses therefrom to contract relevant muscles, thus preventing the occurrence of stress or urge incontinence. Those electric treatment methods have been widely known. The main elements to be stimulated in those methods include the lumbosacral plexus innervating the lower urethra, and a group of muscles forming the pelvic floor (pelvic floor muscle group) and the external urethral sphincter. The stimulating electrodes are usually inserted into anus or vagina, so that they can gain close access to those nerves and muscles from the body surface. To be inserted into vagina, the stimulating electrodes, which are to be connected to a pulse generator, take a plug form 2 cm in diameter and 4 cm in length, while they take a tympanic form of similar size to be inserted into anus. After the electrodes having been attached to the body, repetitive current pulses of a frequency of several to several tens Hz, a peak current of 1-100 mA and a width of 50 .mu.s-5 ms are passed through the body from the body surface.
Generally, pulses with a frequency of several Hz are indicated for urge incontinence while pulses with a frequency of several tens Hz for stress incontinence. The treatment consists usually of delivering electric pulses for 15 minutes once daily and repeating the session for two to four weeks.
During this treatment, the pelvic floor muscle group is stimulated by pulses delivered from the body surface, and put into action. Therefore, dystrophied muscles become activated, and come to have a strength necessary for constricting the passage of urine. This is the reason why this method is effective for the treatment of stress incontinence. To cope with urge incontinence which results from involuntary contraction of the bladder, what is necessary is to stimulate the pudendal nerve arising from 2nd to 4th sacral nerves or its branches, because the impulse from that nerve can inhibit reflexly the involuntary contraction of the bladder, thereby preventing involuntary leaks of urine.
An alternative method, which is also widely known, consists of placing surface electrodes on the external pudendal region or its vicinity to stimulate the pudendal nerve. When sessions comprising repetitive stimulations are repeated over a period, the effect persists even after cessation of the treatment.
It is also known that these treatments are effective for the treatment of bladder pain, frequent urination and bed-wetting as well.
With these methods dependent on the use of plug-type electrodes, however, the patient must insert the electrodes into anus or vagina each time he/she receives the treatment.
This is very disagreeable and humiliating for the patient.
Particularly if children, unmarried women or elderly persons have to be treated with these methods, and they are forced to do such actions for the treatment, they will never fail to feel a strong aversion to such requirements which may, in extreme cases, lead to complete denial of the treatment or treatment continuation. If a strong stimulating current is used to strengthen its effect so that the period necessary for the treatment may be shortened, it may cause pains or, in worst cases, burns.
In view of this, stimulus intensity is gradually raised in a pilot study, and the intensity of treatment stimulation is set to a level which does not cause any discomfort in the patient, or to a tolerable limit. However, the effect of a stimulus varies widely according to the configuration of the electrodes through which it is delivered, and to the sensitivity of the patient. Further, if the patient has a disordered sensitivity, the intensity of stimulus may happen to be so large as to cause him/her burns. Thus, these methods pose many problems which have remained to be solved. These methods further require frequent insertion,/removal of the electrodes into/from vagina or anus, which is necessarily associated with the danger of infection and inflammation. Accordingly, these methods, allegedly non-invasive, are close to an invasive treatment.
To alleviate the above problems, a number of methods have been developed wherein surface electrodes are pasted onto the skin around the pudendal region. However, the same problems still persist: pains and burns are more liable to occur with the progressive increase of stimulation, and daily application/removal of surface electrodes may lead to irritation/inflammation of the involved skin. This method is not acceptable to the patient whose sensitivity is impaired.